Optical communications are used in a wide variety of applications for a wide variety of purposes. For example, in electrically-noisy environments, optical links rather than electrical links may be used to transmit signals due to the immunity of optical links to electromagnetic interference (EMI). An example of such an application is in a factory setting where electrical data transmission lines run alongside electrical power lines that generate large amounts of electrical noise. The electromagnetic noise generated by the power lines can be coupled from the power lines into the data transmission lines, resulting in corruption of the data being transmitted over the data transmission lines. Using optical links to transmit the data can eliminate such problems. As another example, optical links may be used in retail settings to network point-of-sales (POS) terminals. Using optical links for this purpose can eliminate the possibility of sales information being lost or corrupted due to electrical noise existing in the building. As another example, optical links may be used to connect test instruments in manufacturing automated test systems to ensure that correct test data is transferred to the test system controller. These are only a few examples of optical links over which optical communications occur.
In such optical links, an optical transmitter and an optical receiver are located at opposite ends of an optical fiber, which may be a glass optical fiber or a plastic optical fiber. The optical transmitter includes an electrical-to-optical (EO) converter, such as a light-emitting diode (LED) or laser diode, that receives an electrical signal and converts the electrical signal into an optical signal, which is then coupled into the end of the optical fiber. The optical receiver includes an optical-to-electrical (OE) converter, such as a photodiode, that converts the optical signal passing out of the end of the optical fiber into an electrical signal. The optical transmitter and the optical receiver are housing in respective housings that are referred to as optical ports. Each end of the optical fiber is terminated with an optical plug that is adapted to mate with the respective optical port.
One well known series of optical link components that are used for this purpose is the Versatile Link Family (VLF) of components. Although the VLF components are available in a variety of types, the latching configuration for latching the plugs to the ports is generally the same for all VLF types. Each VLF optical port has a pair of flexible arms that are spaced apart and shaped to form a receptacle. The flexible arms are adapted to latch with a latch feature disposed on a cylindrical ferrule of the VLF optical plug as the plug is inserted into the port. The latch feature of the cylindrical ferrule consists of a ridge that extends peripherally about a section of the ferrule, as will now be described with reference to FIG. 1.
FIG. 1 illustrates a side plan view of a pair of flexible arms 2a and 2b of a VLF optical port latched with a ridge 3 of a ferrule 4 of a VLF plug. For ease of illustration the VLF optical port and the VLF optical plug are not shown in FIG. 1. Inside of the VLF optical port, which is sometimes referred to as a header, the end 5 of the ferrule 4 abuts a stop feature 6 formed in an insert 7 of the optical port. The insert has a leadframe 8 embedded therein and a lens 9 formed therein. The leadframe 8 has an integrated circuit (IC) die 11 attached thereto. Electrically-conductive pins (not shown) of the optical port are used to electrically couple electrically-conductive contacts of the IC die 11 to electrically-conductive contacts of a printed circuit board (PCB) on which the port is mounted. The lens 9 couples light between the end of the optical fiber 13 disposed in the ferrule 4 and the IC die 11 of the port.
Although the VLF components work well together, VLF optical ports are not adapted to mate with non-VLF-type optical plugs, i.e., with optical plugs that are not part of the VLF family of components. It would be desirable to provide an optical port that has a versatility that allows it to mate with multiple types of optical plugs, including VLF-type optical plugs and non-VLF-type optical plugs. One advantage of such an optical port is that it would obviate the need, in some cases, to change out the optical port to accommodate the use of a non-VLF-type optical plug already in use in the system. Accordingly, a need exists for an optical port that is capable of mating with different types of optical plugs.